The Codex agency for teams whose agent output stalls in review
OpenAI Codex writes code quickly. Getting that code merged, tested and safe in production is the hard part. Our senior engineers fix the setup around the agent: instructions, sandbox, cloud environments, CI and review. Your team keeps the repository and the result.
For teams with Codex in use and pull requests piling up
- Free 30-minute call
- Paid pilot, one deliverable
- You own the code
Teams we’ve built for
Definition
What is a Codex agency?
A Codex agency is an engineering company that sets up, runs and repairs software delivery built on Codex, the coding agent from OpenAI. It configures the agent’s instructions, sandbox, cloud environments and CI, reviews what the agent writes, and takes responsibility for getting that code into production.
Codex runs in the terminal, the IDE, a desktop app and the cloud. The agent does the typing. Senior engineers still decide the architecture, set the limits, and approve every change that ships.
- Vendor
- OpenAI
- Runs in
- Terminal, IDE, app, cloud
- CLI license
- Apache-2.0, open source
Where it stalls
Why Codex projects stop short of production
The agent is rarely the problem. The setup around it is. Any Codex consultant will recognize these three.
- 01
Instructions get cut off
Codex loads AGENTS.md files up to a combined size cap, 32 KiB by default. Past that it stops adding files, and the agent never sees rules your team thinks it has.
What we do: We split instructions by directory, keep them short, and test what the agent loads.
- 02
Cloud tasks fail on setup
In Codex cloud, secrets are removed before the agent starts and internet access is off by default. Builds that need a private registry or live service then fail without a clear cause.
What we do: We write the setup script, scope network access, and make the environment repeatable.
- 03
Pull requests nobody trusts
The agent opens changes faster than people can review them. Independent testing found coding agents, Codex included, shipping access control and authentication flaws. Codex code review does not replace tests or approvals.
What we do: We add tests, review rules and CI gates, and a senior engineer approves merges.
What we deliver
The work that gets agent code into production
Each item is a deliverable in your repository, agreed before the pilot starts.
Agent instructions and config
Layered AGENTS.md files and a shared config.toml, so every session starts with your build commands, conventions and limits, on every engineer’s machine and in the cloud.
Sandbox and approval policy
Permissions matched to the work. Network access stays off unless a task needs it, then an allowlist limits where the agent can reach. Rules your admins can enforce.
Cloud environments that build
Setup and maintenance scripts, pinned runtimes and scoped internet access, so cloud tasks install, build and test the same way each time they run.
Review and CI gates
Codex code review rules in the repository, the Codex GitHub Action in your pipeline, and tests that must pass before a person approves the merge.
How we work
From stalled setup to a working pipeline
Four steps. You see progress every week and can stop after the pilot.
- 01Call
Free 30-minute call
You show us where the work stalls. We agree the pilot deliverable, scope and price before anything starts.
- 02Audit
Read the repository and the setup
An engineer joins your Slack and repository within five working days of the call and reviews instructions, permissions, environments and recent agent pull requests.
- 03Pilot
Fix one thing end to end
We deliver the agreed fix in your repository, with a weekly demo and a written update.
- 04Handover
Docs, runbooks and training
Your team gets the docs, runbooks and training to run the setup without us. Continue only if it is useful.
Honest fit
When Codex is the right tool
Codex experts should say when the tool is wrong for the job. We do.
The platformCodex
Codex is OpenAI’s coding agent. It reads a repository, edits files and runs commands from the terminal, an IDE extension, a desktop app or cloud containers, inside a sandbox with approval rules, and can review pull requests on GitHub.
Where it is strong
- One agent across terminal, IDE, desktop app and cloud
- Sandboxed by default, with network access off
- Open source CLI under Apache-2.0, with GitHub code review
Where it stops
- Instruction files capped at 32 KiB combined by default
- Cloud agents run without secrets or default internet access
- Code review guides merges but does not replace tests
Codex is the right tool when
- A codebase with tests the agent can run to check its own work
- Well-scoped tasks: features, refactors, migrations, test coverage
- A team that reviews every change before it merges
We would say no when
- No tests and no reviewer: the agent’s errors reach production
- Work that needs production secrets inside the agent’s session
- Architecture decisions you expect the agent to make alone
If another tool fits your codebase better, we say so on the call.
Two ways to work
A scoped build or an engineer on your team
As a Codex development agency we offer two models. Both start with the same free call and a paid pilot.
One deliverable, agreed up front
We fix or build a defined piece of your Codex setup. Scope and price are agreed on the call, before work starts.
- One agreed deliverable
- Weekly demo and written update
- Code in your repository
- Docs and runbooks at handover
A senior engineer in your Slack
A senior engineer joins your team, works in your repository, and runs Codex inside your process and your review rules.
- Joins within five working days
- English, any timezone
- Your tools and your process
- NDA signed on request
FAQ
Questions teams ask us
Short answers, complete on their own.
What does a Codex agency do?
It sets up and repairs the engineering around the Codex agent: instructions, permissions, cloud environments, CI and code review. It also reviews and hardens the code the agent writes, so changes can merge and ship safely.
Why does Codex ignore our AGENTS.md rules?
Codex merges instruction files from your home directory and the repository, up to a size cap of 32 KiB by default. Files past the cap are not loaded. We split and shorten instructions, then check what the agent reads.
Is it safe to give Codex access to our repository?
By default Codex runs in a sandbox, writes only inside the workspace, and has no network access. Risk rises when teams widen those permissions. We set the narrowest policy the work allows and document why.
Can you fix code that Codex already wrote?
Yes. We read the agent’s changes, add the missing tests, and correct access control, authentication and error handling where needed. The fixes land as pull requests in your repository, with a written explanation of each.
How much does it cost?
There is no price list. Scope and price are agreed on the free 30-minute call, before any work starts. The work begins with a paid pilot that has one agreed deliverable, so the initial commitment stays small.
Who owns the code and the configuration?
You do. The code, the IP and the docs are yours. Everything lives in your repository and your accounts, including Codex instructions, scripts and CI workflows. We sign an NDA on request.
Can we hire Codex developers from you directly?
Yes. Besides scoped builds, a senior engineer can join your team and work in your repository. An engineer can be in your Slack within five working days of the free call. The team works in English, in any timezone.
Show us where it stalls
Bring the repository and the pull requests that will not merge. In 30 minutes we tell you what we see, what we would fix, and what the pilot would deliver.
Book a Free 30-Minute Call
We map one workflow that eats your team’s week and show you what an engineer and a few AI agents could take off it. No slide deck, no sales pitch. Just a working session.
Don’t want a call? Email [email protected]
Book a free call- One workflow mapped with you, live
- A clear first step for your team
- Reply within one working day
We worked with Seif on the React Native app for our vehicle-appraisal platform. What stood out most was how much ownership he takes: he thinks a feature through, raises edge cases before they turn into bugs, and delivers something that actually works. And then there is one more thing why I wanted to work with Seif after our very first call: Exceptional clear and consistent communication. It is a pleasure to work with him and his team!
Michael EmaschowFounder, RepairCheck
Seif SgayerFounder ·View LinkedInFree Strategy Call
30 minutes · Google Meet · Free
No packages, no sales pitch. You leave with a clear first step.
- 30 min
- Google Meet
- Calendly
- No commitment
- The plan is yours to keep
- Built for teams at Tabeebi, RepairCheck and MasterPilot
HorizonLux is an independent company. Codex is a trademark of its owner, which does not sponsor or endorse this page.